[c-nsp] etherchannel load balancing

[Aaron]

Does anyone know how etherchannel hashing works when selecting which port to
use ?  When using src-mac load-balancing and iterating straight through 16
mac addresses sequentially by only changing the last hex character one
binary iteration at a time, I see port selections of
2,1,1,2,1,2,2,1,1,2,2,1,2,1,1,2

 

I do see a pattern here..

 

2112

1221

1221

2112

 

But how does this work exactly ?  I mean how does etherchannel go about
deciding that sequence ?

 

Thanks

Aaron

 

Details.

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3330 1111.2222.3334

Would select Gi1/0/2 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3331 1111.2222.3334

Would select Gi1/0/1 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3332 1111.2222.3334

Would select Gi1/0/1 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3333 1111.2222.3334

Would select Gi1/0/2 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3334 1111.2222.3334

Would select Gi1/0/1 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3335 1111.2222.3334

Would select Gi1/0/2 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3336 1111.2222.3334

Would select Gi1/0/2 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3337 1111.2222.3334

Would select Gi1/0/1 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3338 1111.2222.3334

Would select Gi1/0/1 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.3339 1111.2222.3334

Would select Gi1/0/2 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.333a 1111.2222.3334

Would select Gi1/0/2 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.333b 1111.2222.3334

Would select Gi1/0/1 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.333c 1111.2222.3334

Would select Gi1/0/2 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.333d 1111.2222.3334

Would select Gi1/0/1 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.333e 1111.2222.3334

Would select Gi1/0/1 of Po1

 

Switch#test etherchannel load-balance interface port-channel 1 mac
1010.2222.333f 1111.2222.3334

Would select Gi1/0/2 of Po1

 

Switch#sh ver | in IOS

Cisco IOS Software, C3750 Software (C3750-IPSERVICESK9-M), Version
12.2(50)SE3, RELEASE SOFTWARE (fc1)

Switch#

Switch#

Switch#

Switch#sh inven

NAME: "1", DESCR: "WS-C3750G-24T"

PID: WS-C3750G-24T-S   , VID: V10, SN: FDO1535X0N8

 

 

Switch#

Switch#

Switch#sh ether

Switch#sh etherchannel sum 1

                           ^

% Invalid input detected at '^' marker.

 

Switch#sh etherchannel 1 sum

Flags:  D - down        P - bundled in port-channel

        I - stand-alone s - suspended

        H - Hot-standby (LACP only)

        R - Layer3      S - Layer2

        U - in use      f - failed to allocate aggregator

 

        M - not in use, minimum links not met

        u - unsuitable for bundling

        w - waiting to be aggregated

        d - default port

 

 

Number of channel-groups in use: 1

Number of aggregators:           1

 

Group  Port-channel  Protocol    Ports

------+-------------+-----------+-------------------------------------------
----

1      Po1(SU)          -        Gi1/0/1(P)  Gi1/0/2(P)

 

Switch#

Switch#sh etherchannel de

Switch#sh etherchannel detail

                Channel-group listing:

                ----------------------

 

Group: 1

----------

Group state = L2

Ports: 2   Maxports = 8

Port-channels: 1 Max Port-channels = 1

Protocol:    -

Minimum Links: 0

                Ports in the group:

                -------------------

Port: Gi1/0/1

------------

 

Port state    = Up Mstr In-Bndl

Channel group = 1           Mode = On              Gcchange = -

Port-channel  = Po1         GC   =   -             Pseudo port-channel = Po1

Port index    = 0           Load = 0x00            Protocol =    -

 

Age of the port in the current state: 0d:00h:12m:27s

 

Port: Gi1/0/2

------------

 

Port state    = Up Mstr In-Bndl

Channel group = 1           Mode = On              Gcchange = -

Port-channel  = Po1         GC   =   -             Pseudo port-channel = Po1

Port index    = 0           Load = 0x00            Protocol =    -

 

Age of the port in the current state: 0d:00h:12m:27s

 

                Port-channels in the group:

                ---------------------------

 

Port-channel: Po1

------------

 

Age of the Port-channel   = 0d:00h:17m:00s

Logical slot/port   = 10/1          Number of ports = 2

GC                  = 0x00000000      HotStandBy port = null

Port state          = Port-channel Ag-Inuse

Protocol            =    -

Port security       = Disabled

 

Ports in the Port-channel:

 

Index   Load   Port     EC state        No of bits

------+------+------+------------------+-----------

  0     00     Gi1/0/1  On                 0

  0     00     Gi1/0/2  On                 0

 

Time since last port bundled:    0d:00h:12m:27s    Gi1/0/2

Time since last port Un-bundled: 0d:00h:12m:27s    Gi1/0/2

 

Switch#

Switch#

Switch#

Switch#

Switch#sh port-c

Switch#sh etherc

Switch#sh etherchannel lo

Switch#sh etherchannel load-balance

EtherChannel Load-Balancing Configuration:

        src-mac

 

EtherChannel Load-Balancing Addresses Used Per-Protocol:

Non-IP: Source MAC address

  IPv4: Source MAC address

  IPv6: Source MAC address

 

Switch#